Switching regulators have achieved wide popularity in recent years due to the need for efficient DC-to-DC power conversion in many applications. Such switching regulators include, for example, buck regulators, boost regulators, buck-boost regulators, and the like.
In general, switching regulators operate by switching a reactive circuit “on” and “off” in such a way that energy from the input voltage source is transferred to the output load with a minimal loss of energy while converting the input voltage to a different output voltage. The resulting output voltage is then a function of the duty cycle of the switching signal, and may be less than the input voltage (buck regulator), greater than the input voltage (boost regulator), an inverse polarity of the input voltage (buck-boost), or a combination thereof.
Currently known switching regulators are unsatisfactory in a number of respects. For example, because such circuits involve fast switching of current (“input current”) through an inductive element, a significant amount of noise or electromechanical interference (EMI) is often generated by the circuit. While various filters may be incorporated to reduce this noise, such filters are only partially effective, and can add significant cost and size to the system.
Accordingly, it is desirable to provide switching regulators with reduced input current noise. Other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.